One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,3)(5,6)(7,14)(8,12)(9,17)(10,13)(11,15)(16,19)(18,20)(5,7)(6,11)(8,15)(9,18)(10,16)(12,19)(13,20)(14,17) involution — undirected(5,6)(7,11)(8,12)(9,17)(10,13)(14,18)(15,19)(16,20) involution — undirected(1,3,4,2)(5,6)(7,11)(8,17)(9,12)(10,13)(14,15)(16,20)(18,19)(5,8,10,9)(6,12,13,17)(7,15,16,18)(11,19,20,14)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.